Cable



April18,1933. F. M. PQTTER 1,904,525

' CABLE Filed Feb. 4. 1928 5 [8 j; ffl f f4 /0 f3 /Z/Q 1 ff Z5 u Z720 Z] Frank/ Po//e/ rarenfedapr. 1s, 1933 1,904,525

UNITED STATES PATENT OFFICE t FRANK M. POTTER, vOF ROME, NEW YORK,l ABSIGNOR TO GENERAL CABLE CORPORA- TION, OF NEW YORK, N. Y., A CORPORATION OF JERSEY CABLE appncamn mea February 4, 192s. 110,251,765.

The present invention relates to insulated the cable btdoes not provide the desired long electric cables and particularly to conductors life since the steel Jacket soon rusts away which are adapted for use in earthen trenches, leaving the lead exposed and easily puncin yards of industrial plants, and other places tured and subject to crystallization or elec- 5 where cables are usually subjected to extrolysis because of direct contact with the 50 tremes of weather, heat, cold abrasion and soil. Also the jointing of leadcable is exlike'conditions of service. Certain features pensive since highly skilled Workmen are reof the invention, however, as will be pointed quired to wipe the joints and such skilled Outhave a more general application and may workmen are usually not available in small be associated advantageously with cables of communities. According to the present in- 55 many other diierent'types than those which vention a cable is provided which is practicalare especially discussed herein. Among the ly egual to lead sheathed cable from the objects'of the invention are the rovision of stan point of moisture resistance but which electrical conductors or cables w ich will be 1s very much less expensive to purchase and particularly resistant to heat, moisture, soil install than lead cable and which, under exw acidity, alkalinity, oxidation, abrasion or acting conditions of service, has a considerimpact; which will be relatively inexpensive ably longer expectancy of life than lead to manufacture and which, in the enumerated cable.

and other respects, will be eminently satis- When laid along undulating surfaces factory for t-he purposes for which they are cables of known types, and particularly 65 designated. plural conductor cables, by reason of the val- Further objects of the invention will be apleys between conductors for which no satisparent from the following description of two factory filler has heretofore been provided, representative embodiments thereof. have wicked moisture entering through small The present invention has been developed punctures or faulty joints along their length 70 to provide a non-metallic sheathed cable to toward low sections to cause rotting at such supplant metal (usually lead) sheated cables low points. The present invention not only in uses for which the latter have been found provides a cable which eiectually prevents unsuited either because of their inherent dethe entry 0f external moisture but One Which iiciencies, because of their relatively exces- Will not permit the traveling or wicking of 75 sive expense, or because of objectionable charmoisture along the valleys to collection points acteristics, such as inductiono For example where it might' cause damage. Attempts in rural communities and in smaller towns it have been made to provide a non-metallic is quite customary to lay cables in shallow type of cable for use in earthen trenches and earthen trenches without any protective while fairly good results have been attained so covering. While lead covered cable has for short periods o time after the installaproved highly satisactory when used in untion where single conductor cables have been derground vaults or tunnels it h used and these separate cables laid a congiven considerable trouble when l' sidcrable distance apart, there has not been 40 inthe ground because of the ease with which. produced, so far as applicant is aware, a cable se it is punctured. For this re son when 'il ci this type which does not quickly decovered cable has been buried he groans t teriorate ano. ailow leakage of moisture 'therehas been supplied with a stee strip or in with consequent electric leakage or short to protect it 'rom abrasion or nis circuits between the 'sevcrai conductors., b-

not oniy increases the already" oi? viously the expense of providing and instalse ling several separate single conductor cables is considerable and even with their inherent high cost and disadvantages lead cables have been used in preference to the available nonmetalliccables.

A feature of the present cable which, as stated above,'may be em loyed with advantage in other types of ca le, is the putty or compound which is employed to seal the valleys between conductors in plural vconductor cables and which also is used to saturate the braids of the cables to prevent the state is quite plastic and is but slightly affected even by great temperature changes or age and hence will not become too -soft or brittle; that is, it has a low susceptibility factor. Even when the cable has lain in the ground for long periods of time it may be bent repeatedly without causing cracking of its sheath and, when the cable is punctured, the putty, because it thus maintains its plastic state, will tend to flow or migrate toward .the rupture and heal or seal the same.

The accompanying drawing shows the preferred and illustrative embodiments of the invention and therein:

Fig. 1 is a plan view of a two conductor cable having the several sheaths of material progressively removed to show the interior construction Fig. 2 is a cross section on the line 2-2 of Fia l;

Fig. 3 is a plan view similar to Fig. 1 but showing a modified form of cable; and

Fig. 4 is a cross section taken on the line 4 4 of Fig. 3.

"in Figs. 1 and 2 of the drawing an insulated cable provided with two metallic conduct-ors 10 is illustrated. Preferably each conductor 10 is served with a thin paper separator 11 to insure free stripping and over this the usual vulcanized rubber coating 12 is provided. A single Wrap of rubberized tape 13 which may be of different colors for dii'erent conductors for the purpose of identitication is applied tightly. over the rubber coating 12, after which a iibrous braid 14, preferably of cotton, is provided. The cotton braid is thoroughly saturated with a penetrating waterproofing preparation 15 which may include asphalt, Montan wax and paraffin, followed by a coating 16 of weather and moisture-proofing putty which penetrates or impregnates the cotton braid,

thoroughly caulking the same, and is squeezed or wi d off to leave a relatively thick unbroken film over the braid.

Prior to the provision of the putty specified above no material known has provided the required degree of dielectric strength, waterproofing, heat and oxidation, resistance, and continued plasticity required to build a cable which would be inexpensive and yet have a long life and give satisfactory -service underground. This plastic oxidationand moisture-resistant compound may be composed of a base of al fatty acid pitch such as stearin pitch, and a mineral filler such as asbestine. The asbestine which is in a finely divided state is added to the pitch in the amount required to give the desired consistency which preferably, at normal atmospheric temperatures is about like glazing putty and at 300 F. about like cold molasses. The amount of asbestine added will vary with the consistency of the pitch but will be between 10% and 30% of the whole. If a putty of a higher viscosity is desired as for filling the valleys of large conductor cables, fibre 'asbestos may also be added with the asbestine as a filler. Other mineral fillers, such as alumina, ground quartz, mica or magnesium oxide may be substituted for the magnesium silicate if desired.

, Individual conductors covered as set out above are assembled in the r uired number for the cable. rlhey may be lai parallel or be twisted as desired. Usually if only two conductors are used they are laid parallel and if more are used they are twisted.

The valleys between the assembled conductors are filled with an oxidationand moisture-resistanty putty compound of the type described, a suiiicient amount being used to provide a thin wiped coat 17 of the same about the whole assembly. Since the putty maintains its fiuidity it follows that it will tend to flow or migrate toward and heal or seal any bruise or rupture that may later be made to the completed cable. The blow of pick for example will usually merely separate theindividual conductors and since the valleys between them are filled and each conductor has a separate sheath of the putty it is more than likely that the metallic conductors will remain protected.

An asbestos sheath 18, preferably braided. covers the assembly over the filling and covering coat 17 of putty. Asbestos is employed in preference to cotton or` other availabl; materials for the braid because it will not rot; will not wick moisture along the braid as cotton will do to some extent no matter how thorough a saturation has been attempted; will take moisture proofing saturants to a much higher degree than most materials. and once saturated will not absorb moisture in the event of minute mechanical defects in the cable or carelessly made taps 'may comprise copper oleate, petrolatum,

paraliin and cresylic acid may be served on the cable. A cable which is somewhat less expensive but which still possesses the desired characteristics to a great extent may be made by omitting the folded paper tape' or by substituting therefor a paper or cloth tape saturated with a compound containing copper oleate and a filler such as sulfur or a sulfur compound. Over this fibrous sheath 21 an- 'ing sheath 37 of other coat 22 of putty is applied. This coat is wiped to leave a relatively thick unbroken film of caulking material over the tape.

Finally a tough and strong sheath 23 of a. fibrous stranded material such as pressure saturated jute is closely and tightly served, finished with a waterproofing compound 24 such, for example, as asphalt and covered with soapstone or talc 25.

The cable illustrated in Figs. 3 and 4 coml prises conductors 3() each provided with a rubber sheath 32. A cotton braid 34 impregnated with a waterproofing saturant 35 is formed over the rubber sheath 32. This may, if desired, be coated for each individual conductor with the fatty acid base putty but, as shown, the individual coating is omitted and only the valley iilling and assembly coatputty is applied. A cotton braid 47 is next applied, followed by a saturation of material similar to 15 and a coat 48 of putty. By making the cotton braid quite open and providing a coating of putty on both sides, the wicking of moisture along the cotton braid is greatly minimized, particularly where an vouter cover of asbestos braid is provided as will be noted. 4

Next a sheath 41 of moistureproofed kraft paper or other fibrous moistureproofing material is wrapped about the cable. This is covered with putty 49 and an asbestos braid 38 is formed over the latter. The braid is treated with a. moistureproof saturant 39 similar to that indicated at l5 and given a heavy surface coating 40 of putty. A tightly wound twisted twine sheath 43 is next applied and this sheath is saturated with a substance 44 similar to 15, covered with a coating of moistureproofing material 44al such as asphalt, and finally a coating of talc or soapstone 45 is dusted over the cable. Pressure impregnated jute may be substituted forthe twine, in which case the saturant 44' is omitted.

The embodiment othe invention in either of the forms described provides 'a homogeneous compact structure-which is relatively inexpensive to manufacture and yet/. possesses qualities quite superior to those ofthe usual metallic covered cables provided .for this purpose and qualities which havenot been produced at all in any other non-metallic conductor heretofore proposed.

Although only two embodiments of the invention have been shown and described here' in it will be understood that the invention may be variously modified and embodied within the scope of the appended claims. What I claim is:

1. An article of manufacture comprising in combination, metallic electrical conductors, a surrounding sheath of paper for each conductor. ay sheath of rubber for each conductor over said paper. a serving of rubberized tape for each conductor over said rubber, a cotton braid saturated with waterproofing material over said tape, a coating of oxidationand moisture-resistant compound containing stearin pitch and asbestine wiped over said braid for each conductor, a valley filling and overall covering of said compound for said assembled conductors, an asbestos braid sheath for the cable over said compound, a waterproofing material and a coat of said compound applied to said asbestos sheath, an oleate impregnated paper sheath, a coating of said compound over said oleate paper sheath, a jute cord serving over said compound and waterproofing material and talc applied upon said jute serving. v

2. An article of manufacture comprising in combination, metallic electrical conductors, a surrounding sheath of rubber insulating compound for each of said conduct-ors, a putty compound including stearin pitch and asbestine filling the valleys between adjacent covered conductors and covering the assembled conductors, a fabric braid over said compound coating, a coating of said putty compound over said braid. a moistureproofed paper tape sheath between layers of said putty compound and a jute sheath covering the whole.

3. An article of manufacture comprising in combination, a plurality of separately insulated electrical conductors, a putty compound including a fatty acid pitch and asbestine filling the valleys between and covering said several conductors in assembly, and an asbestos braid -saturated by and disposed between coatings ot' said compound, and a fabric jacket surrounding the whole.

4. An article of manufacture comprising in combination, a metallic electrical conductor, a rubber sheath encasing said conductor, a protection for said rubber sheath comprising a braid and a plastic compound coating for said braid, a further protecting casing .comprising a braid and paper tape each impregnated with and disposed adjacent a layer of plastic oxidationand moistureresistant compound, said compound includa fatty acid pitch together with a mineral er.

6. An article of manufacture comprising in combination, a plurality of insulated electrical conductors, a plastic compound illin the valleys between said conductors, said compound being resistant to heat, oxidation,

moisture, earth acids and alkalis and retaining its plastic state for prolonged periods of time, and a fibrous jacket enclosing the whole.

7 An article of manufacture comprising in combination, a plurality of insulated electrical conductors, and a protecting covering therefor comprisin a plastic compound including stearin pitc and asbestine filling the valleys between said conductors and a substantially non-wicking fibrous sheath.4

8. An article of manufacture comprising in combination, a plurality of insulated electrical conductors, a plastic compound including stearin pitch, asbestos and asbestine filling the valleys between said conductors, and a sheath of mineral fiber -surrounding the whole.

9. An article of manufacture comprising, in combination, a pair of conductors, se arate covering means for each conductor inc uding a coating of an oxidationand moisture-resistant compound, and a common rotective covering for both conductors inclu ing a valley ller of said compound.

10. An article of manufacture comprising, in combination, a pair of conductors, separate protectin means for each conductor includlng a coatmg of an oxidationand moisture-resistant compound, and a common rotective covering for both conductors inc uding a valley filler of said com ound, an asbestos sheath and a layer of said) compound surrounding said asbtos sheath.

11. An article of manufacture comprising, in combination, a pair of conductors, separateprotecting means for each conductor including a coating of oxidationand moistureresistant compound, and a common rotective covering 'for both conductors inc uding an asbestos sheath impregnated with said compound and an additional separate coating of said compound.

`12. An article of manufacture comprising, in combination, a metallic electrical conductor and a covering therefor, said covering including a fibrous coating and an oxidationand moisture-resistant compound impregnating and covering the same, said compound including a fatty acid pitch and magnesium silicate.

13. An article of manufacture comprlsing,`

14. An article of manufacture comprising,

in combination, a metallic electrical conductor and a covering therefor, said covering including a fibrous coating and an oxidationand moisture-resistant plastic compound covering the same, said com ound including a base of fatty acid pitch an a mineral filler.

15. An articleof manufacture comprising, in combination,a metallic electrical conductor and a covering therefor, said covering inoluding a fibrous coating and an oxidationand moisture-resistant compound impregnating and cover the same, said compoun including asbestme and stearin pitch.

16. An article of manufacture comprising, in combination, aV metallic electrical conductor and a covering therefor, said coverin including a plurallty of fibrouscoatings an an oxidationand moisture-resistant compound separating the coatings, said compound including a base of fatty acid pitch and a mineral filler.

17. An article of manufacture comprising, in combination, a metallic electrical conductor and a covering therefor, said coverin including a' plurality of fibrous coatings and an oxidation- `and moisture-resistant compound impregnating and separating the coatings, said compound inclu i and stearin pitch.

18. An article of manufacture comprising a metallic conductor, and protective means com risingaI protective body and a plastic oxi ationand moisture-resistant compound lpluding a fatty acid pitch and a mineral 19. An article of manufacture comprising a metallic conductor and covering therefor comprising a fibrous material and a plastic compound including steal-in pitch and an asbestos-like filler.

20. An article of manufacture comprising, in combination, a metallic conductor, and a covering therefor comprising a compound remaining plastic throughout wide temperature changes, said com und including a fatty acid pitch and a mlneral filler.

21. An article of manufacture comprisfing, in combination, a plurality of electrical conductors associated to ether so as to form valleys therebetween, an a valley filler therefor comprisin a plastic compound resistant to heat, oxidation and moisture and retaining ng asbestine its plastic state for indefinite periods of time.

22. An article of manufacture comprising, in combination, a plurality of electrical conduct'ors, and a valley filler therefor comprising a plastic compound including a fatty acid pitch base and apmineral filler.

23. An article of manufacture comprising, in combination, a plurality of electrical conductors, and a plastic compound in the valleys between said conductors, said compound including stearin pitch and magnesium silicate.

24. An article of manufacture comprising, in combination, a dplurality of electrical conductors associate together so as to form valleys therebetween, and a protecting covering t erefor, including a compound resistant to heat and to moisture and retaining its plastic state for indefinite eriods of time, said compound being dispose -in the valleys between said conductors.

2 5. An article of manufacture comprising, in combination, a plurality of electrical conductors, and a protecting covering therefor, including an oxidationand moisture-resistant compound positioned inthe valleys between said conductors and characterized by continued plasticity with wide temperature coverin changes so as to tend to migrate toward and heal bruises or ruptures in said covering.

26. An article of manufacture comprising, in combination, a metallic electrical conductor, a protecting covering over said conductor including a fibrous jacket and a plastic insulating oxidationand moisture-resistant compound over said conductor, said compound including a fattyacid pitch and a mineral filler, and a yfibre jacket over. the Whole.

' 27. An article of manufacture comprising, in combination, a plurality of separately insulated conductors and a common protective for said conductors including 'ba fibrous jacket, a plastic oxidationand moisture-resistant compoundl and a surrounding ibrous jacket having a moisture-proofing compound applied thereto.

28. An artlcle of manufacture comprising in combination, a plurality of separately insulated conductors having a waterproofing saturantapplied thereto, a coating of an oxidationand moisture-resistant compound over said plurality of conductors and extending into the valleys therebetween, and a protective coverin surrounding the whole.

29. An artic e of manufacture comprising in combination an insulated metallic electrical conductor, and a protective covering therefor, said covering including a sheath of non-wickin fibrous material, and a protective layer o an oxidationand moistureresistant plastic com und adjacent to and j signed my -name to this specification this 2n day of n February, 1928. v lFRANK M. 

